#ifndef _WX_OVERLAY_H_
#define _WX_OVERLAY_H_

#include "wx/defs.h"

#if defined(wxMAC_USE_CORE_GRAPHICS) && wxMAC_USE_CORE_GRAPHICS
#define wxHAS_NATIVE_OVERLAY 1
#elif defined(__WXDFB__)
#define wxHAS_NATIVE_OVERLAY 1
#else
// don't define wxHAS_NATIVE_OVERLAY
#endif

// ----------------------------------------------------------------------------
// creates an overlay over an existing window, allowing for manipulations like
// rubberbanding etc. This API is not stable yet, not to be used outside wx
// internal code
// ----------------------------------------------------------------------------

class wxOverlayImpl;
class wxWindowDC;

class wxOverlay {
  public:
    wxOverlay();
    ~wxOverlay();

    // clears the overlay without restoring the former state
    // to be done eg when the window content has been changed and repainted
    void Reset();

    // returns (port-specific) implementation of the overlay
    wxOverlayImpl *GetImpl() { return m_impl; }

  private:
    friend class wxDCOverlay;

    // returns true if it has been setup
    bool IsOk();

    void Init( wxWindowDC* dc, int x, int y, int width, int height );

    void BeginDrawing( wxWindowDC* dc );

    void EndDrawing( wxWindowDC* dc );

    void Clear( wxWindowDC* dc );

    wxOverlayImpl* m_impl;

    bool m_inDrawing;


    DECLARE_NO_COPY_CLASS( wxOverlay )
};


class wxDCOverlay {
  public:
    // connects this overlay to the corresponding drawing dc, if the overlay is
    // not initialized yet this call will do so
    wxDCOverlay( wxOverlay &overlay, wxWindowDC *dc, int x, int y, int width, int height );

    // convenience wrapper that behaves the same using the entire area of the dc
    wxDCOverlay( wxOverlay &overlay, wxWindowDC *dc );

    // removes the connection between the overlay and the dc
    virtual ~wxDCOverlay();

    // clears the layer, restoring the state at the last init
    void Clear();

  private:
    void Init( wxWindowDC *dc, int x, int y, int width, int height );

    wxOverlay& m_overlay;

    wxWindowDC* m_dc;


    DECLARE_NO_COPY_CLASS( wxDCOverlay )
};

#endif // _WX_OVERLAY_H_
